Insider trade on Splunk acquisition?

I don't know if this is genuinely suspicious or not. Is buying 20K of options an unusual thing? Or is this something that happens regularly with options expiring worthless or with a small gain - and it just happened to hit big this time?

IE "someone bought a lottery ticket and won" - interesting to know if they play the lottery every other day (and don't usually win?)

Buying 20k of options when there's a 99.99% chance of them being worth $0 is pretty unusual, unless you're actively regularly trading in the millions.